Shock absorber



y 1952 J. J. WELLER 3,035,825

snocx ABSORBER Filed Aug. 19, 1960 INVENTOR (/bH/V I M/ELLE 2 Q MATTORNEY United States Patent Cffice 3,035,825 Patented May 22, 19623,035,825 SHOCK ABSORBER John J. Weller, Allentown, Pa., assignor toStandard Plastics, Inc., Fogelsville, Pa., a corporation of PennsylvaniaFiled Aug. 19, 196), Ser. No. 50,724 6 Claims. (Cl. 267-1) Thisinvention relates to an article of manufacture, and more particularly toa resilient article suitable for use as a cushioning device or bumper inpackages, crates, and the like.

In shipping fragile articles there exists the problem of protecting thearticle against damage while in transit. The classic, although obsolete,technique for protecting articles in their shipping crates is thestufling of wastepaper, excelsior or rags between the article and thesides of the crate. This technique was never very successful because,among other reasons, it depended on the knowledge of the personpreparing the crate to stuff the proper amount of paper or waste betweenthe article and the sides of the crate. If an insuflicient amount ofpaper were stuffed into the crate, or if the paper were not properlylocated, the article very often became damaged in transit. Furthermore,such techniques are not adequate for the protection of relatively heavyobjects having delicate components.

Eventually the classic technique of using waste-paper as a stuflingmaterial was replaced by corrugated cardboard. The corrugated cardboardwas cut into suitable sizes for wedging the article within the crate.Corrugated cardboard, however, is subject to crushing. Frequently,therefore, articles which were cushioned by the located cardboard becamedamaged because the corrugated cardboard became crushed in transit andlost its cushioning ability.

Accordingly, it is a primary object of this invention to providecushioning means especially suitable for use in boxes, shipping crates,and the like, which is resilient, inexpensive to manufacture and, whichis not subject to any of the shortcomings of the conventional cushioningmeans.

It is a further object of the invention to provide a uniquely shaped,unit-handling cushioning device made of a soft foamed resilient materialhaving the property of breathing.

Another object is to provide a unit-handling cushioning device whichwill make optimum use of the resilient material thereof, by eifectivelyeliminating loss of supporting efiiciency at outer limits thereof.

It is a feature of this invention to provide a cushioning device whichretains its general shape, under conditions to which such articles arenormally subjected.

In accordance with an aspect of the invention the cushioning devicecomprises a foam-plastic body member having relatively stiff set-in orconcave ends to provide aresilient knee-action response to forcesapplied to the top and bottom of the article. The shape of the articleand its end stiffness are obtained by reinforcing means which, in oneform, surrounds four sides of the article; in other forms, separateend-reinforcing members are used.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following descriptionin conjunction with the accompanying drawing. In said drawing, whichshows, for illustrative purposes only, preferred forms of the invention:

FIG. 1 is a perspective view of a preferred form of the novel cushiondevice; and

FIGS. 2 and 3 are fragmentary perspective views of alternative forms ofstiffening member in modified cushion devices.

The basic part of the cushioning device is a foamed resilient material,such as foam rubber or plastic which has the property of breathing. Apreferred foam-plastic material for use in the invention is a flexibleelastovrneric cellular plastic such as polyurethane, sometimes known asurethane foam. By way of interest, cellular products of polyurethanematerial are formed from liquid polymeric reaction mixtures containingpolyisocyanates. The reaction mixtures are polymeric materials which areeither liquid at room temperature or capable of being melted atrelatively low temperatures. The polymeric materials contain activehydrogen atoms which react with the isocyanate groups to form a networkof cross-linked molecular chains. A polyisocyanate functions as acrosslinker or curative for the polymeric material and also reacts withwater provided in the liquid reaction mixture to form carbon dioxide,which causes the liquid reaction mixture to expand and foam, whereby aflexible, cellular structure is formed which retains its foamed cellularcharacter after the polymer has been cross-linked or cured.

The foamed character of the material is an essential characteristicwhich imparts the desired degree of resiliency to the cushion device.Moreover, since the material is foamed it has the property of breathingwhereby, once polymerized, the cushion device is not subject topermanent deformation.

Referring now to FIG. 1, the cushion device, as for use in ordinaryshipping crates, comprises a reinforced body member 1, preferably madeof polyurethane material having the characteristics described above. Thepreferred shape is generally cubic or rectangular prismatic, having atop side 2, bottom side 3, and end sides 4-5.

The end sides 4-5 of the cushion device are set-in or concaved apredetermined amount from the top and bottom sides 2-3. Preferably, theset-in end sides are in the shape of a V, the angle of the V beingapproximately The end sides 2-3 are of reinforcing material and have theproperty of reducing and efiectively eliminating endeifects which resultin bulging and loss of support at the ends of unreinforced foammaterial. This being the case, the overall resilient load capacity for agiven size cushion device is increased by the reinforcing end sides ofthe invention.

Reinforcing the end sides 4-5 may be accomplished in a variety of ways.In the form of FIG. 1, a peripherally continuous cardboard structurecomprises the top side 2, end 5, bottom side 3, and end 4, allcontinuously and effectively integrally joined to each other. The grainor corrugations of the card-board preferably extends in the direction ofperipheral continuity, as suggested by shading on parts 2-5. Inpractice, the basic cardboard shape 2-53-4 is retained between twoparallel plates to define the mold for the resilient material while itis expanding and until it has set or polymerized. What were open sides(as at 6) then become exposed generally flat sides of the resilient body1, and the foam plastic is caused to bond itself to the retaining andreinforcing cardboard.

In use, the cushion device will be placed between two articles to besubjected to shock, as for example between a crate inner wall and anobject to be protectively supported within the crate. Generally, severalsuch cushions will be used to support various sides of the object withinthe crate. As to any particular cushion, the top surface 2 may besecured to or rest against the crate wall, and the opposite surface maybe secured to or rest against the object. A preloaded resilient supportaction is achieved if the crate is designed to squeeze the cushionagainst the object.

In the presence of squeezing preload, or in the presence of shockproducing a squeezing action on the cushion, any tendency of the foammaterial to bulge at the ends 45 is not only resisted by thereinforcement provided by cardboard at 45, but the stiffness of the legs78 at end 5 and the foam-cardboard adhesion in shear (at 12 and at 13)impose articulation at folds 11-1213 (at end 5), While the stifiness oflegs 9-10 at end 4 and the same adhesion in shear impose articulation atthe corresponding folds between parts 2-9--103 at end 4. Thisarticulation effectively converts the end reinforcing members or legs 78and 9-10 into pistons working against each other to increase the loadingpressure on the resilient body -1, to a level well in excess of thatattributable solely to normal forces on surfaces 2-3. As a result, agiven body of resilient material is caused to perform a more efiicientjob of both steady and transient load support.

As indicated, in *FIG. 1 the reinforcing material extends peripherallyof body 1, and articulation at corners such as 11-13 depends uponadhesion of 'body 1 to surfaces 23. The main point is that corners, asat 11, shall not spread or displace outward-1y in the presence ofcompression. Continuity of top and bottom members 2-3 positively assurestension in these members, to avoid such spread.

Although the reinforcement material has been described as cardboard, itwill be understood that other materials such as sheet metal, e.g.,aluminum or steel sheet may also serve the purpose. Also, thereinforcement may be a composite of materials, as for example, cardboardat 7--8 and 10, secured to each other by strips or by a continuous beltof lnraft paper, in which case the top and bottom surfaces would bepaper, preferably including a fibrous or woven reinforcement toWithstand tension.

In FIGS. 2 and 3, I show modifications in which separate endreinforcement members are employed. In FIG. 2, end member 5 generallyresembles the fully exposed end of FIG. 1, and it comprises legs 7'8'and top and bottom flanges 1415 bonded to one end of a resilient body,suggested at 1. Member 5 may be of cardboard, metal, or the like, aslong as the desired articulation can be achieved with relative freedomat 1112'13, as will be understood.

In the form of FIG. 3, the end member 5" is smoothly concaved, as ofarcuate form at 16, with top and bottom flanges 17-18'. When bonded tobody 1", and in the presence of top-bottom compression, the are 16deforms somewhat uniformly to create a more distributed inward lateraladditional compression on the ends of body 1". If corrugated cardboardis used in FIG. 3 for reinforcement member 5', then the corrugationspreferably run at right angles to the direction indicated in FIG. 1,thus assuring'uniform bending throughout the are 16.

It will be seen that I have described an improved cushioning devicewherein the reinforcement combines with the resilieent material toproduce a result exceeding the sum attributable/to the parts alone. Bymy knee-action reinforcement, the resilient body delivers optimizedperformance.

While the invention has been described in detail for the preferred formsillustrated, it will be understood that modifications may be made withinthe scope of the invention as defined in the claims which follow.

I claim:

1. A cushion device, or the like, comprising a foamed resilient bodyhaving top, bottom and opposed end sides, the opposed end sides beingset-in a given amount from the top and bottom sides, andsnrface-stiffening means carried at said opposite end sides andconforming to the set-in contour of said ends, said stiffening meanscomprising corrugated cardboard, the stiff direction of the corrugationsextending from end-to-end and from top-to-bottom along the opposite endsides.

2. The device according to claim 1, wherein said corrugated cardboardstiffening means encompasses said top, bottom and end sides, thecardboard being coextensive with said sides and bonded thereto.

3. The device according to claim 1, wherein said setin end sides are Vshaped.

4. A cushion device, or the like, comprising a foamed homogeneousresilient body having top, bottom front, rear and opposite end sides,each of said end sides being set-in a given amount from the top andbottom sides, and surface stiffening means conforming to the setincontour of said ends and extending from said top side to said bottomside and bearing against said opposite end sides, respectively, thefront and rear sides being substantially free of said stiffening means,said stiffening means serving to maintain the shape of said device.

5. The device according to claim 4, in which said set-in end sides arearcnate.

. 6. The device according to claim 4, wherein said stiffening meansincludes sheet metal.

References Cited in the file of this patent

